Interpolymer of di-(secondary butyl) itaconate and ethyl methacrylate



Patented Apr. 14, 1942 v UNITED STATES PATENT OFFICE INTERPOLYMER. F DI-(SECONDARY ETHYL BUTYL) METHACRYLATE Gaetano F. DAlelio, Pittsfield,Mass, assignor to General Electric Company, a corporation of New York NoDrawing.

ITACONATE AND Application September 12, 1939,

Serial No. 294,493

2 Claims.

alcohol residue and, in addition to said ester,

at least one other polymerizable compound con taining the structure moreparticularly a p CH =0 grouping Specifically the invention is concernedwith a composition comprising the product of polymerization of a mixturecontaining di-.(secondary butyl) itaconate (di-s-butyl itaconate) andethyl methacrylate in the ratio of, by weight, 5- parts of the former to95 parts of the latter, which polymerization product has a higherilexural strength and a higher impact strength than ethyl methacrylatewhen polymerized alone under similar conditions.

The new esters prepared and used in prac- +-ticing this inventionconveniently may be defined as itaconic esters in which at least oneester group contains at least three and less than five saturated carbonatoms in the alcohol residue. Examples of such -esters are monopropylitaconate,

' c H2=C'C 0 OH 7 11100003111 methyl propyl itaconate,

CH==CC o OCH:

\ HICQOCIHT and ethyl butyl itaconate,

'cm=cc o 0 01H;

H30 0 O 04H It will be noted that the two last-named esters are mixedesters, the preparation of which is in general somewhat dimcult andcomplicated, in-

volving extensive processing and high cost. The mono esters are notdifilcult to make but no particular advantages ordinarily accrue fromtheir use in the production of interpolymers. Hence, the preferredembodiment of this invention comprises the preparation, and utilizationin the production of interpolymers, of diesters of itaconic acid inwhich both ester groups are identical (symmetrical diesters) for examplethe dipropyl and the dibutyl esters. The mixed and symmetrical itaconicdiesters with which this in-,

vention is especially concerned may be graphically expressed by theformula capo-coon N 'mcooa' where R and R are alkyl radicals containingat least three and less than five saturated carbon atoms in the alcoholresidue and are the same or narily, it would be expected that estersintermediate to the polymeric ethyl and the amyl esters likewise wouldbe" hard, brittle masses. Surprisingly, the polymeric propyl and butylesters of this invention varybetween viscous or soft, non-flowing massesto resilient, stiff masses.

In carrying the present invention into efiect the normal and isomericforms of aliphatic monoand di-esters of itaconic acid containing threeor four saturated carbon atoms in the alcohol residue-of the estergrouping may be polymerized separately, or mixed with each other, ormixed with other polymerizable material. The homogeneous andheterogeneous polymers of this invention vary from viscous masses torubbery and hard, solid bodies, depending upon the extent ofpolymerization and. the particular polymerizable or other modifyingagent, if any,

' bility in the monomeric or partially polymerized itaconic esters. Therate of polymerizationis a function of the temperature and may becarried out at from room temperature .(20-30 C.)

to temperatures materially above 100 C.,for example about 130'? C.

The monomeric propyl, butyl and propyl butyl itaconic esters whenpolymerized alone iorm thermoplastic materials, that is, materials theshape of which easily can be changed by heat. The softening point,solubility and other properties of these itaconic esters depend upon thenumber of carbon atoms in, and the structure of, the ester chain. Ingeneral, the longer the ester chain, the lower is the softening point ofthe polymer. Some of the completely polymerized mide and fluoride,acrylic and methacrylic esters, e. g., methyl acrylate, ethyl acrylate,propyl acrylate, butyl acrylate, methyl methacrylate, ethylmethacrylate, propyl methacrylate, 'butyl methacrylate, etc.

As illustrative of the diii'erences in properties resulting frominterpolymerizing the itaconic esters with which thisinvention isconcerned with other polymerizable materials, the following ismentioned:

Dibutyl itaconate which had been polymerized in the presence of 1% by,weight benzoyl peroxide for about 3 days atapproximately 70 C. showedconsiderable flow at that temperature.

= The same material when copolymerized under the same conditions withonly by weight of diallyl itaconate formed aiirm, non-flowing gel in 1hour and set within, 3 days to a hard, clear, colorless, highlyheat-resistant copolymer that was insoluble in solvents, such as acetoneand benzene, in which the dibutyl itaconate, which had been polymerizedalone, was soluble.

esters are clear, colorless, rubbery solids. Others are soft,free-flowing, viscous masses at temperatures of about 100 0., yet highlyviscous or soft, slightly mobile masses at, room temperature.

Some possess properties intermediate to the} aforementionedcharacteristics.

In manyapplications the normally viscous, mobile polymers of highplastic flow are exceptilizing materials'that'can accommodate themselvesto the form of the container are required. Particularly are theyvaluable when used alone, or whendissolved or dispersed in otherdielecsuch .as mineral oil. This property of high plastic flow can be togreat commercial advantage in molding processes by interpolymerizingthese monomers with other bodies of low plastic flow, thereby impartingthe desired flow characteristics to the end-product;

In other cases, ior example where to prepare products of highersoftening point or of decreased brittleness and solubility, or toproduce insoluble, infusible products. this may be done bycopolymerizing a selected monomeric or partially polymerized ester ofthis invention with polymerizable unsaturated materials in monomeric orpartiallyp'olyiuerized state, forexample an ester of a polybasic acid inwhich atleast two ester groups each contain an unsaturated hydrocarbonradical, more particularly a cm=c radical such vinyl, allyl, methallyl,etc. Also, copolymers of valuable properties'may be obtained bycopolymerizing propyl, or butyl, or propyl butyl itaconate with othermonomeric or partly polymerized itaconic esters, for example, di-

methyl itaconate, diethyl itaconate, itaconic itis desired s Asaffurther illustration the following example also is given. A.solutionof 5 partssecondary butyl itaconate (di-s-butyi itaconate) and95 parts ethyl methacryiate was treated with0.25

1 part benzoyl peroxide for 23 hours at C. and

for 24 hours at C., yielding a hard, clear copolymer. The material wasextremely ductile tionally valuable, particularly where non-volaandcould not be broken. in a ilexural strength test. Ithad an impactstrength (Dynstati of 0.164 ft. lb. Ethyl methacrylate, polymerizedalone under similar 'conditions,broke;in 'a flexural strength test at1450 pounds per square inch tric materials including a liquidhydrocarbon and hadan impact strength of 0.135 foot pounds.

Various methods maybe used to prepare the esters with which thisinvention is concerned. For example, they may be prepared by esterexchange reactions in the presence of a suitable inhibiting agent, suchas phenolic bodies, cop- .per, etc., and a suitable catalyst, thereaction proceeding as man alcoholysis. Thus, in the preparation of, forinstance dibutyl; itaconate,

.the reactants may comprise butyl alcohol, di-

methyl or diethyl itaconate, hydroquinone asan I inhibiting agent and acatalyst such as metallic sodium, potassium carbonate, sulfuric acid,etc.

'The esters of this invention alsomay be pre-.

pared'irom itaconic nitrile by causing to react therewith an alcohol,corresponding to the ester desired; inthe presence of water and aninorganic acid. 01', they may bemade from itaconyl chloride and aselected alcohol, or by decomposition of a corresponding ester of citricor citraconic acids or one of their derivatives.

A preferred method oi preparation is by direct esteriflcation ofitaconic acid withthe selected alcohol in the presence of anesteriflcation catalyst, with or without the presence ofother unreactivebodies to remove the water resulting from esteriiication. This methodmay. be caresters of unsaturated alcohols. for instance dially]itaconate,.etc; vinyl and allyl esters of saturated and unsaturatedmonoand poly-carboxylic acids, etc., more particularly withpolymerizable materials containing a 1 CHFC grouping for instancemonomeric. or partly polymerized styrene, vinyl esters such as theacetate, chloride,

bromide, fluoride, etc., vinyl 'lretones, meth-vinyl ketones, vinylidenehalides as the chloride, "-broried out continuously.

The mixed esters of this invention, that is itaconic esters in whichboth ester groups are different, also may be prepared in various ways.

Illustrative of such esters arepropyl butyl its- 'conate, n-propylisobutylsitaconate, virsopropyi n-butyl itaconate, isopropyl isobutylitaconate, propyl sebutyl itaconateand n-butyl t-butyl itaconate Thesemixed esters may be prepared." for instance, by reaction betweenitaconic monoester' acid [chloridefand a selected alcohol in thepresence orabsence'oi' an inhibitlnl agent such as phenolic bodies,copper, etc. .They also 1 may be made by ester exchangereactionlin'thepresence of a. suitable catalyst, using an ester of a lower boilingalcohol, such as dimcthyl or diethyl itaconate, and an alcoholcorresponding to the ester desired.

Another method of preparation of these mixed esters is from itaco'nicmcnoacid chloride and a selected alcohol, followed by directesteriflcation of the other acid radical by another alcohol. These mixedesters also may be made by direct consecutive esteriflcation of each ofthe carboxyl groups with different alcohols, or by treating itaconicdi-acid chloride first with one alcohol, then with another. They alsomay be prepared by saponiflcation of one group of an itaconic diesterwith alcoholic potassium hydroxide in the cold and either isolating themonoacid from the potassium salt for further reaction with the selectedalcohol or causing the potassium salt to react directly with an alkylsulfate corresponding to the ester desired.

In order that those skilled in the art better may understand how thepresent invention may be carried into effect, the following illustrativeexamples are given of the preparation of these new esters and of variouscompositions comprising the same. Allparts are by weight.

Motto-prom! itaconate The mono-potassium salt of mono-propyl itaconateester was prepared by the slow addition of a solution of 100 partsdipropyl itaconate in 100 parts absolute alcohol to 26.1 parts potassiumhydroxide dissolved in 235 parts absolute alcohol, followed by gentlerefluxing for about 3 hours. The mono-potassium salt was. isolated byevaporation of the solvent alcohol and freed from any potassiumcarbonate formed by extracting the ester salt with benzene or petroleumether or some other suitable solvent. When dried at 85-l00 C., 43.9.parts of the ester salt was obtained. The free mono-propyl ester ofitaconic acid was isolated by the addition of 22 parts of hydrochloricacid solution to the potassium salt. The acid mono-ester was isolated byevaporation to practical dryness of the above solution, followed byextraction with absolute alcohol to eliminate potassium chloride.

Dipropyl itaconate 195 parts itaconic acid, 210 parts propyl alcohol,180 parts benzene and 5.9 parts sulfuric acid (95.5%) were refluxed in acontinuous esteriflcation apparatus until no more water ofesteriiication was given off. The residual liquid was washed first witha 10% solution of NazCOs, then with water, after which it was filteredand distilled. A colorless distillate of dipropyl itaconate, boilingpoint 94-98 C. at 1.5 mm. pressure, was obtained.

A sample of dipropyl itaconate was polymerized by incorporating therein0.5% by weight benzoyl peroxide and heating for approximately 38 hoursat 90-100 C. 'The polymeric material was a soft, non-flowing mass.

Similarly the following esters were prepared: (a) Di-isopropylitaconate, boiling at 87-95 C. at 2.5 mm. pressure, It washeat-polymerized to a quite stifi, resilient mass which was slightlytacky at room temperature. (1).) Di-butyl' itaconate, boiling at 159-162C. at 14.5-15 mm. pressure. It polymerized to a non-flowing polymer,slightly softer than similarly polymerized di-propyl itaconate. (c)Di-isobutyl itaconate (an ltaconic diester of a branched chain butylalcohol), boiling at 95-99 C. at 1.5 mm. pres- 'sure. It polymerized toa non-flowingmass,

slightly softer than similarly polymerized di-isopropyl itaconate.boiling at 108-112 C. at 1.5 mm. pressure. It

polymerized to a viscous fiowable resinous 'body'. (e) Di-s-butylitaconate (an itaconic diester of a branched chain butyl alcohol),boiling at ,95P-100 C. at 1.5 mm. pressure. It polymerized to a viscousmass, slightly softer than similarly polymerized di-isobutyl itaconate.

The following examples are illustrative of the Example 1 This exampleillustrates the production of twocomponent copolymers utilizing the newesters of this invention.

coplfly' (h t 1' mer za- 1 arac er stics Components tion time ofcopolymcr in hours (a) 5 parts di-isopropyl itaconate 120 Rubbery.

5 parts vinyl acetate (b) 50 parts di-isopropyl itacon- 72 Clear,colorless,

ate slightly soft. 50 parts methyl acrylate (c) 50 tigrts di-lsopropylitucon- 72 Hind, clear, color- 8 ess. 50 parts ethyl acrylate (d) 50parts di-isopropyl ltacon- 48 Hard, tough, clear, ate 7 colorless. 50tparts methyl methacryla e (e) 50 pearts di-lsopropyl itacon- 72 Clear,colorless. a w

50 parts propyl methacrylate (I) 50 parts di-rsopropyl itacon- 72 Do.

a e 50 tparts n-butyl methacryla e (a) 50 itiarts di-isopropyl itecon-72 Do.

a e 50 parts isobutyl methacrylate (h) 60 parts di-isopropyl itacon- 48Do.

40 paarts isobutyl methacryla l (i) parts di-isopropyl itacon- 72 Clear,colorless,

' ate thermosetting.

20 parts diallyl itaconate (j) 50 parts dibutyl itaconate 48 Clear,colorless,

50 parts vinyl acetate rubbery. (k) 50 parts dibutyl itaconate 72 Soft,opaque.

50 parts styrene (I) 80 parts dibutyl itaconate 1 Solid gel hard, 20parts diallyl itaconate 72 clear, colorless,

thcrmosetting (m) 50 parts dibutyl itaconate 24 Slightly soft, clear,

5) parts methallyl methacrylthermoscttiug. a e (1:) 5parts dibutylitaconate 48 Clear, colorles.

5 parts methyl methacrylate somewhat rubbery tough. (o) 50 parts dibutylitaconate 24 Hard, translucent, 50 parts ethylene glycol almost opaque,dimethacrylete thermosetting. (11) 5 parts s-butyl itaconate, 23Translucent, hard,

55 C. 24 clear. 95 parts ethyl methacrylate,

C; 0.25% benzoyl peroxide ('1) 5 51221168 s-butyl itaconate, 18 Hard,translucent.

5 parts methylmethacrylate, 24

85 0.. 0.25% bcnzoyl peroxide Unless otherwise stated the interpolymersof this example are thermoplastic. The addition of as little as 0.1 partof a polyallyl ester of a polycarboxylic acid, specifically diallylitaconate, to the mixed monomers results in interpolymers of (d) .Propyl,butyl itaconate.

4 increased swims-assess, heat-resistance, or

produced. I v

- 4 This example the production oi three-component utilizing the newesters of this invention. I

. Ooploly- C l me saharactc a component's 1 tion time of copolymerinhours 1 c 43pertsdipropylitsmnaie 48 Clear, colorless, 1 43 portsvinyl acetate, slightly soft. g H 14 parts ethyl scrylate (b) 45 partsdlpropyl liaconate 4i;v Herd, colorless, 45 ports diethyl itaconatethermosotting, 10 ports glycol dlmethecrylete clear. (c) 6 partsdi-isopropyl itsconete 72 Hard, clear.

2.5 parts vinyl acetate 2.5 parts methyl methscrylate i 1 (d) 37.10parts dl-lsopropyl ltacon- 48 Hard, tough, clear. a i, 37.1;a partsmethyl methacryla v 25.0 parts ethyl acrylate (e)eopartsdi-isopropylitaconete 48 Somew hat rub- 33 partto s lso-butylmethecrylbery, clear.

, a 17 parts methyl acrylste r (1) Imports dihutyl itaconate 12) Hard,translucent.

25 pertsmcthyl methlcrylate 25 parts styrene (q) 50 parts dibutyllteconate. 120 Translueent,somc- ,25 parts vinyl acetate what rubbery.

25 parts styrene (h) 5 parts dlbutyl itaconate 72 Tough.

2.5 parts vinyl acetate I 2.5 tgents methyl methacryle i I f v (i) 37.5ports bidutyl itaconate 48 Very viscous parts isobutyl methacryla e37-.5 parts styrene 1 (j) 40 parts propyl itaconnte, l Non-flowable mass7 90 C. resilienuzel 0.5% benzoyl peroxide 2V.- v 10 parts ellylitaconate lli 50 parts ethyl methaerylate Hard. (k)40pertsbutylitsconate,90C-. 1 Do.

0.5 benzoyl peroxide 10 ports allyl ltaconate 2% 50 parts ethylmethacrylate; 11%

Example 3 This example illustrates the production of fourcomponentcopolymers utilizing Cow;- (h ete u mel'ualei-arises m? tion time ofwpolymer in hours (a) 37.5partsdi-isopropylltscon- -48 Translueen'ghard,ate i tough.

12.5 parts n-hutyl methacryllztpartsethylscrylete j I 37.5pertsvinylacetate Y (b) 33%perts dl-isopropylitecon- 1 48 Clear, viscous.

a I 109 parts n-butyl methscrylate" v 22;: parts ethyl acrylate 33pertsstyrene' I -(c) 30 ports di-isopropylitaeon- 48 Clear, colorless, 7ate somewhat solt.

llpertemethylrnethecrylste Y lopertsmethylacrylete v wpertsstyrene v (l)Spartsdlbutyliteconste 24 Hard,.trm slueent.;'

' spertsvinylecetete I 3 parts methyl methacrylste 1 port styrene pExample 4 v 'l'hisexample the production-cited: I polymers utilizingdibutyl itoconate and, wherein at least one ojt the components is inpolymerized state prior to copolymerization.

is tiontime v oieopelymer hours (a town butylitacomte .1 as can rubbeJlOpgrtsPn-butylmeihscrylthermoplastic." t wpertePdibutyliteconaie 48 Sihtl solt trans- O dillmethylmethleryl- V i (c) kwpertsldibutylltsconatea Translucent, are

' wpertl lvinylecetete y y (d) gpertsgdibutylitsconate I 36 Viscousparts one 7 t. i (c) eo'parts Pi ilbutyl itaconute 48 Viscous, ftronslui v ceu mpertsPsgrene (f) to -m P butylitsconste 1 48 Robbery,translutopertslethl late cent. I (g) topertsrdihntylitsconste so Herd,opaque, so arium y methserylthsrmoeettlug. (h)fiopertsPdisbutylitoconete ac Thermosettlng 50 ports-ethylene glycol(11- opaque.

methecrgate (i) 33 parts dibu litsconate 48 Soit,clesr gel.

' pertsl'dime ylltaoontillpertsdiallylmaledte I i Thediallyl itaconate,the rnethallyl methacrylate, the glycol dimethacrylate and the diallylmaleate used in production of the copolymers of the above illustrativeexamples may be increasedvor may be replaced in whole orin'partbysubstances such, for instance, as ,allyl and methallyl esters ofpolybasic acids, lor'example, by diallyl carbonate, diallyl oxalatediallyl malodiallyl hydromucate, dlallyl glutinaic, tetrallylsymmetrical ethane tetracarboxylate, etc.; by

other polyhydric alcoholand unsaturated alcohol esters of acrylic andmethacrylic acidsyi'or example, glycol acrylate, allyl acrylate, allylmethacrylate, methallyl acrylate, etc.; or bymixtures of suchsubstances.The itaconic esters of this invention, as well as the interpolymersobtained by copolymerizing these esters with other polymerizable bodies,

have a wide range of properties. Their hardness and solubilitles maybevaried over aconsiderable range from fluid compositions of variedintrinsic viscosity 011.80; flexible. bodies to hard, rigid masses thatcan be. swelled, or dissolved plastic material, the-itaconic esters ofthis invention are particularly suited tor that purpose.

High molecular'weight bodies such as polyvinyl chloride, cellulose.nes'terssuch as the acetate,

propionate, butyrate, etc., cellulose ethers such as methyl cellulose,ethyl cellulose, benzyl cellulose, etc.; polymerized methylmethacrylate, polystyrene, etc may be plasticized by incorporatingtherewith these new itaconic esters in monomerlc, partially polymerizedor completely polymerized' state, in the presence or absenceoi aapartiall y catalyst such as benzoyl peroxide when the monomeric orpartially polymerized forms are used. The itaconic ester may beincorporated into the high molecular weight body by simple mechanicalagitation or by the use of mutual solvents;

followed by the standard mechanical processes known to the plastics art.These bodies then may be subjected to further heat and pressuretreatment if desired.

The esters of this invention may be converted to polymers orinterpolymers in molds with or without the application of pressure, inthe presence or absence of a material which is a solvent for the monomerbut not for the polymer, or one which is a solvent for both monomer andpolymer, or one which is not a solvent for either the monomer or polymerso that spongy or granulated polymeric modifications are obtained.

The solid, thermoplastic polymers and copolymers of this invention, withor without modifying agents, may be used in injection, compression, ortransfer molding processes to make numerous articles for industrial,technical and novelty use and other applications.

As modifying agents, various fillers may be used, for example, woodflour, alpha flock, sand, asbestos, mica, paper, cloth, cellulosederivatives such as cellulose itself, regenerated cellulose, celluloseesters, cellulose ethers, natural and synthetic filaments or fibers,etc., in continuous, shredded, or comminuted form. Pigments, dyes,opacifiers, plasticizing substances, such has dibutyl phthalate, estersof monobasic and polybasic saturated and unsaturated acids, esters ofaromatic monobasic and polybasic acids, etc. may be incorporated intothe polymers and copolymers of this invention to modify the same.Synthetic and natural resins, gums, oils, waxes, polyhalogenatedaromatic derivatives, etc., likewise may be added as modifying agents.

In solvents, or without solvent utilizing a melt process, the fusiblepolymers may be used in adhesive and laminating applications, to bondpaper, wood, mica flakes, glass sheets, rubber sheets, fibrous materialssuch as silk, asbestos, glass fibers, synthetic fibers in filament,thread or fabric (woven or felted) form, cellulose derivatives in sheet,comminuted or fiber form, etc. In the form of liquid coatingcompositions such as varnishes, lacquers, enamels, etc., they findapplication in surface protective coatings, such as for walls, desks,wire, concrete, porcelains, etc. In a flowable condition without the useof solvents they may be used as impregnants for many porous bodies, suchas cork, pottery, felts, or fabricated bodies with interstices, such asthe windings of electrical coils, netted fiber, interwoven fibrousmaterials, etc.

When the monomers of this invention are copolymerized with, for example,diallyl itaconate in the presence of another non-polymerizable bodywhich acts as a solvent for these monomers, there results a homogeneousgelled material which firmly binds the solvent so as to reduce to aminimum evaporation losses of the solvent. Illustrative ofnon-polymerizable bodies which thus may be gelled are butyl alcohol,benzene, ethylene dichloride, the monohalogenated aromatic hydrocarbonsor mixtures of halogenated aromatic hydrocarbons, ethylene glycol,mineral oils including lubricating oils, etc.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A composition comprising the product of polymerization of a mixturecontaining di-s-butyl itaconate and ethyl methacrylate in the ratio of,by weight, 5 parts of the former to 95 parts of the latter, saidpolymerization product having a higher fiexural strength and a higherimpact strength than ethyl methacrylate when polymerized alone undersimilar conditions.

2. The method of producing a product having higher impact and fiexuralstrength characteristics than polymeric ethyl methacrylate whichcomprises forming a mixture containing monomeric ethyl methacrylate anddi-s-butyl itaconate in the ratio of, by weight, 95 parts of the formerto 5 parts of the latter and, in addition to said monomers, a smallamount of a polymerization catalyst, and heating the said mixture toGAEIANO F. D'ALELIO.

